"Motor Trend is one of my favorite magazines. I'm a car fanatic," he says. (Editor's note: thanks for kudos, Steve!) "I've bought your magazine multiple hundreds of times in airports over the years. A lot of airports."

When he can drive, he does, and his daily drivers are a 2012 Mercedes-Benz S550 and a 2010 Dodge RAM 3500, which he calls the Cadillac of trucks.

"I've been a Mercedes guy for years," he says. "I've never had a truck and saw this 2010 Dodge when I saw this commercial and I said, 'I want a f-cking truck' because I need something to tow my boat. Every one of my friends that gets in the truck, they say, 'This is like a Cadillac.'"

Harwell gives the Dodge a 9 rating. "I wouldn't trade it for the world. They created a really classic, rugged, kick-your-ass, never-break-down vehicle that feels like you're almost in a Bentley inside. It's got the room, it's got all the luxury, all the amenities of a modern-day, luxury car. It really is a great truck."

The only thing that prevents it from being a perfect 10 is the back end feels a bit too light. "So it does bounce a little too much for me," he says. "There's not enough weight back there. Those are just little things I think manufacturers overlook -- I think they just overlook the back half if the truck. Cars are generally more distributed. Trucks, especially when you get a king cab, or a long bed, it gets lighter as it goes to the rear of car. But I'll give that up to have the power that I have. The torque in my truck is second to none."

2012 Mercedes-Benz S550
Rating: 9
"My first car I bought when I got signed to the music business was a BMW 525 four-door. It was like, 'Wow, I actually have enough money to buy this car? I was eating Taco Bell two weeks ago.' The BMW was the best-handling car I've ever owned. But Mercedes gave me the room, the luxury to where I literally could put the seat back far enough where I couldn't touch the pedals, and that's very rare in a car."

He also likes that the S550 is a very quiet, smooth, and yet responsive ride. "They're not really quick off the bottom end; it feels almost like someone is winding up a rubber band and cutting it loose. It doesn't really kick in. A BMW, they've got a lot of low-end torque, but the high end, I would take a Mercedes over that. There are things on a Mercedes that I like a lot more than other cars that I've owned."

He gives the S550 a 9 rating, partly because he prefers the older body style. "If you're going to go spend $70,000 on a car, you should cover the details. I want the air conditioning blowing up my ass in the seat. I want icicles hanging off my lip is what I want," he says with a laugh. "I want to be able to adjust if I'm hypothermia mode or if I'm in Mexico."

Harwell has owned a lot of cars. He's been through Range Rovers, which he liked, until he got tired of sitting so high in the seat. "You can't really adjust the seats that much. I feel like the car should be like a race car, where you're sitting way down at the bottom, and that's what Mercedes always gave me. I feel like I'm in a cockpit of a supercar, because when you're sitting down in the seat, because you feel like you have more control."

He grew up riding motorcycles and he says riding high in a seat reminds him of sport bikes. "You sit on top of these street bikes and you're almost leaning over it," he says. "It's uncomfortable, even though they look great. You feel like a passenger. I don't want to feel like a passenger, I want to feel like I'm in control of the car, or the motorcycle."

Of all the cars he's owned, Harwell's favorite car was a Cadillac EXT he regrets selling. "It was the cat's meow. It was the bronzy-looking gold color, with the tan leather," he describes. "Talk about a car that had everything -- that's the car everyone should model a truck or luxury car off of. It had everything. I wasn't really worried about the speed and torque and horsepower. When you got in it, you felt like it was part of you."

1951 Hudson Hornet
Rating: 12
Recently Harwell's uncle died and he inherited his mint condition 1951 Hudson Hornet, which he tried to buy from his uncle for years.

"When I got it here, all my neighbors came out," he says. "It still has the factory plastic on the seats, it's got a flat-six and the old push-button start in it. I've got a piece of my family history. My uncle took the time out to leave it to me and nobody knew he was sick. All of a sudden some gentlemen calls and says, 'I have a car for you, a '51 Hudson Hornet.' I said, 'What?' It was super emotional."

Harwell always has project cars and he's finishing up working on his 1972 Toyota Land Cruiser FJ40, which fans might recall he once posed with for a Rolling Stone article. "That was the first car that my dad and I bought when my mother passed in 1989," he says. "It was a father-son project and I had built it up through the years and about 10 years ago I was doing a photo shoot for Rolling Stone out in Las Vegas where I used to live, and flipped it, almost killed myself, and I decided to rebuild the whole thing from the ground up. It's my hot rod version of a four-wheel drive."

The article didn't show Harwell flipping the car, which was an accident. "It was soft powder desert dirt and I started doing donuts. The rear end caught a rut and spiraled up and flipped. The photographer was in such in shock he held his hand on the camera, it took every photo. The very last photo was of me crawling out of the Land Cruiser.

Car learned to drive inHarwell grew up in San Jose, where his grandmother taught him and his siblings how to drive in a 1970s Chrysler Cordoba.

"She had her Chrysler Cordoba with an eight-track in it," he says. "Being young and dumb, we'd be at a Burger King drive-through and I'm doing burnouts as we're waiting for our meal in this Chrysler Cordoba. My grandmother's favorite saying, 'Baby, you've got me working button holes over here,' those little buttons in the seats, meaning she'd be pulling on those because I made her so nervous. And she'd start whistling. I remember having Ted Nugent 'Cat Scratch Fever' on the eight-track and I used to play both sides of it," he says.

He remembers those days fondly, and luckily he didn't pick up her bad driving habits. "The thing about my grandmother that I always remember and makes me smile, my grandmother had her right blinker on for 45 years. She just never turned off her right blinker. If my grandmother would leave our house, it's like a bad commercial -- she'd wait till she hit the car in front and hit the car in back, to know what her stopping point was. She would whistle and do her thing, she was oblivious to anything around her, but hey, God bless her, she drove until she was 70-something years old."

Harwell also grew up driving a 1972 Ford Ranchero. "It had a 351 Windsor in it and my dad passed it on to me when I was old enough to take it to high school," he says. He would drive it to nearby Baylands Raceway to race it on Wednesdays.

"My dad drove for UPS and he worked swing shift -- my dad doesn't know I have the car. I drove out to Baylands Raceway, as I'm driving there, I see this UPS truck and I'm thinking, there's no way my dad is right there," he says, laughing. "I passed my father in his own car, to go to Baylands Raceway to drag my dad's car. I look up and my dad points at me. I'm going, 'Oh, shit, I just passed my father in his own car, which he doesn't know I'm driving; I'm uninsured,' but he laughed. My dad always knew I was kooky because I grew up racing go karts. When I was a kid, my other life, I'd be a race car driver. I literally would eat and sleep racing."

First car boughtHarwell's dad bought him an old Ford Courier pickup truck, and Harwell traded it for a 1960 Volkswagen Beetle ragtop, which was also the first car he painted. "My father bought me an old Ford Courier, which I chopped the top off and made it my little mini truck. My friend was really into it and he traded me my Volkswagen and that's when I got into Volkswagens. Back in 1989 and '90s, I had the biggest Volkswagen club in Northern California. It was called Club V-Dub."

His VW club would go to all the shows and they wore club shirts and would meet at the bowling alley on Thursday nights. "That's when I started working with metal and stretching fenders and smoothing out dashes in cars," he says. "That's when I first started learning how to weld and my bodywork skills came into play."

When Harwell was a kid, he'd take apart his dirt bike and rebuild it. "One of the most interesting aspects of me being a motorhead, my neighbor Joe Wilhelm, he's in the Hot Rod Builders Hall of Fame, would sit there and work the metal, no Bondo," he says. "Joe is really one of the keys to me loving cars. I would walk to school and I'd see him pounding metal. He really inspired me to love cars. Unfortunately he passed from a brain tumor, which a lot of people thought was brought on by using lead on cars instead of Bondo."

Favorite road trip"My father had a Lincoln Continental, suicide doors, white on black interior, electric windows, all the amenities, and we used to travel every summer to Colorado to see my mom's sister," he recalls. "You'd have five kids and my grandmother and my mom in the car. I think I grew up smoking a pack in the day, by secondhand smoke. Nobody thought about lung cancer."

His father later sold that Continental for $600. "What that car would be worth today. My dad always had cars. We had an old MG. My first hot rod we built was an old '23 T-Bucket with a small-block Chevy in it, black with yellow flames on it." Harwell used to drag race the T-Bucket on the nearby El Camino Real. "Music pays my bills but motors make my life," he says.

Smash Mouth's cookbook and new album
During the interview, Harwell is at his stove making homemade pasta sauce, and he's talking about finding a place with a man cave so that he can fix cars and have friends over at a barbeque pit. "I'd rather have a little shop separate from my house and have my toys. Working on cars is my therapy," he says.

He also enjoys cooking and has written a new cookbook called "Recipes from the Road." The foreword is written by good friend and former Celeb Drive Guy Fieri. "I'm a foodie, that's why I'm cooking spaghetti right now. When I met Guy, Guy was catering a party that I did, and if you ask Guy, he totally ripped my second look off, he'll tell you straight up," he says. "If I still had my spikey blond hair, him and I could be brothers standing next to each other. Guy always wanted to be the rock star and now he is."

The cookbook isn't just recipes from chefs. It also has stories from Harwell's many years on the road. "What I love about the cookbook is with every town and city we've been over the past 20 years, there's a story," he says. "There's some funny-ass shit that happened in those towns. That's what made the book special and that's why Guy was so into it. He was like, 'Dude, I've never seen nothing like this.'"

Smash Mouth's 1997 debut was the hit "Walkin' on the Sun." In recent years the band has also focused on entertaining the troops at bases in Afghanistan, Iraq, and Guam. The new album "Magic" features the band's signature sound. For more info and tour dates please visit www.smashmouth.com.